Micro Systems Flashcards
dominant flora in skin
staph epi
dominant flora in nose? what can colonize the anterior nares?
stap epi; staph aureus colonizes
dominant flora in oropharnyx
strep viridans
Dominant flora in a dental plaque
strept mutans
2 Dominant flora of the colon
bacteroides fragilis > E.coli
dominant flora of the vagina? what 2 species can colonize it?
lactobacillus; colonized by E. coli and GBS
what is significant about neonates delivered by C-section in terms of normal flora?
they have no flora at birth, but are rapidly colonized after birth
which 2 bugs cause food poisoning that starts rapidly and ends rapidly?
Staph aureus; Bacillus cereus
2 bugs that cause food poisoning from contaminated seafood
Vibrio parahemolyticus; Vibrio vulnificus
Which bug can cause wound infections from contact with contaminated water/shellfish?
Vibrio vulnificus
Food poisoning from reheated rice?!
Be serious = Bacillus cereus
Food poisoning from meats, mayonnaise, and custard via a pre-formed toxin
Staph aureus
food poisoning from reheated meat dishes
clostridium perfringens
food poisoning from improperly canned foods? what might be a hint?
clostridium botulinum. bulging cans are suspicious
food poisoning from undercooked meat such as hamburgers?
E. coli O157:H7
food poisoning from poultry, meat, or eggs
Salmonella
name 3 bugs that can mimic appendicitis
- yersinia enterocolitica = MCC mesenteric adenitis of peyer’s patches
- non-typhoidal salmonella = mesenteric adenitis of peyer’s patches
- campylobacter jejuni
name 7 bugs that cause bloody diarrhea
(C)an’t (S)top (S)***ting (E)(E)r(Y)throcyt(E)s
- Campylobacter (Puppies, livestock, ingestion of undercooked meat)
- Salmonella (Lactose neg, flagellar motility, has animal reservoir, esp. poultry & eggs)
- Shigella (Lactose neg, very low ID50, produces Shiga toxin; human reservoir only)
- EHEC (can cause HUS; Shiga-like toxin)
- EIEC (invades colonic mucosa)
- Yersinia enterocolitica (daycare outbreaks; pseudoappendicitis)
- Entamoeba histolytica (also “anchovy-paste” exudate on liver abscesses)
comma- or s-shaped organism that grows at 42C and causes bloody diarrhea
Campylobacter “likes the campfire” @ 42C
lactose negative organism with flagellar motility. has an animal reservoir, especially poultry and eggs. causes bloody diarrhea
salmonella
lactose negative. very low infectious dose. humans are the only reservoir for this toxin-producing bad boy. causes bloody diarrhea
shigella
O157:H7 is a strain of this bug. causes bloody diarrhea, HUS, and makes a shiga-like toxin
EHEC
gram negative rod that invades the colonic mucosa and can cause bloody diarrhea
EIEC
day-care outbreaks + pseudoappendicitis + bloody diarrhea
yersinia entercolitica
protozoan that can cause bloody diarrhea
entamoeba histolytica
name 4 bacteria, 2 protozoa, and 2 viruses that cause watery diarrhea = 8 total
- ETEC (Traveler’s; ST & LT toxin)
- Vibrio cholera (comma-shaped; rice-water)
- C. difficile (can also cause bloody diarrhea; Pseudomembranous Colitis)
- C. perfringens (also causes gas gangrene)
Protozoa:
Giardia, Cryptosporidium (immunocompromised)
Viruses:
Rotavirus, Norovirus
name 2 bugs that cause pneumonia in neonates < 4 weeks old
GBS + E.coli
name 5 agents that cause pneumonia in children ages 4 weeks - 18 years, 1 viral + 4 bugs
- RSV
- Mycoplasma
- Chlamydia trachomatis (infants - 3 y/o)
- Chlamydia pneumoniae (school-aged kids)
- S. pneumoniae
(R)unts (M)ay (C)ough (C)hunky (S)putum
name 3 bugs that cause pneumonia in adults ages 18-40 years
mycoplasma
c. pneumoniae
s. pneumoniae
name 5 agents that commonly cause pneumonia in adults 40-65 years old
S. pneumoniae
H. influenzae
Anaerobes
Viruses
Mycoplasma
name 5 agents that commonly cause pneumonia in the elderly > 65 years old
S. pneumoniae
Influenza virus
Anaerobes
H influenzae
Gram negative rods
Name 2 groups of bugs that cause nosocomial pneumonia (HAP)
Enteric gram negative rods
(Klebsiella, Pseudomonas aeruginosa, & E. coli)
Staphylococcus species
Name 5 common (general classes) causes of pneumonia in immunocompromised patients
- Staphylococcus species
- Enteric gram negative rods
- Fungi
- Viruses: CMV (post-transplant), RSV, influenza
- PcP (HIV patients)
which group of bugs commonly causes aspiration pneumonia?
Anaerobes
(Clostridium, Bacterioides, Actinomyces)
also: Fusobacterium & Peptococcus
name 3 bugs that may cause pneumonia in alcoholics or IV drug users
S. pneumoniae
Klebsiella
Staph aureus
Name 3 bugs that commonly cause pneumonia in CF patients
Pseudomonas
Staph aureus
Strep pneumo
Name 3 bugs that commonly cause pneumonia after a viral infection
Staphylococcus
H. flu
Strep pneumo
Most common causes of atypical pneumonia
Mycoplasma (most common)
Viruses (most common in kids)
- influenza viruses, adenoviruses, rhinovirus, RSV
- also may arise after childhood exanthema like rubeola (measles) or varicella (chickenpox)
Others:
- Legionella
- Chlamydia (Ornithosis, via inhalation of dried excreta of infected birds)
- CMV (post-transplant, immunosuppressive Tx)
- Coxiella burnetii (ricketsial; Q fever; farmers & veterinarians)
name 3 bugs that cause meningitis in newborns < 6 months old
GBS
E.coli
Listeria
name 3 bugs + 1 group of viruses that cause meningitis in children ages 6 months-6 years
Strep pneumo
Neisseria meningitidis
H. flu type B
Enteroviruses = polio, echovirus, coxsackie
name 2 bugs and 2 viruses that cause meningitis in patients age 6 years - 60 years. Of these, which is most common in teens?
S. pneumo
N. meningitidis = most common in teens
Enteroviruses = polio, echo, coxsackie
Herpes = HSV 2 for meningitis, HSV 1 for encephalitis
Name 3 bugs that cause meningitis in patients > 60 years old
Strep pneumo
Gram negative rods
Listeria
What two drugs should be started empirically when bacterial meningitis is suspected? What should you add if listeria is suspected?
ceftriaxone + vancomycin (add ampicillin for Listeria)
Name 5 common viral causes of meningitis
Enteroviruses = coxsackie + echo + polio
HSV = HSV-2 meningitis and HSV-1 encephalitis
HIV
West nile virus = arbovirus
VZV
Name 4 common causes of meningitis in HIV infections
Cryptococcus = chronic fungal meningitis
CMV
Toxoplasmosis = protozoal brain abscesses
JC virus = progressive multifocal leukoencephalopathy (PML)
Which bug has greatly decreased incidence of meningitis due to development of a conjugated vaccine 10-15 years ago? Who is most often affected today?
H. flu (Cases are seen in un-immunized children today)
What leads to these findings in CSF?
increased opening pressure
increased PMNs
increased protein
decreased sugar
bacterial meningitis
What leads to these findings in CSF?
increased opening pressure
increased lymphocytes
increased protein
decreased sugar
Fungal or TB Meningitis
What leads to these findings in CSF?
normal or slightly increased opening pressure
increased lymphocytes
normal or slightly increased protein
normal sugar levels
viral (aseptic) meningitis
which bug should you assume as the cause of osteomyelitis if no other info is available?
staph aureus
osteomyelitis in a sexually active person?
N. gonorrhoeae, but more commonly causes septic arthritis
name 2 bugs that cause osteomyelitis in DM or IVDU patients
pseudomonas
serratia
osteomyelitis in sickle cell folks
salmonella (and they ain’t tryna get no pain meds)
2 bugs that cause osteomyeltis in prosthetic replacements
staph aureus + staph epi
what bug can cause vertebral osteomyelitis?
M. TB = pott’s disease
osteolmyelitis in a patient that presents with cat and dog bites or scratches?
pasteurella multocida
in which patient population does osteomyelitis occur most often? what are classic, but non-specific findings?
most occurs in children
elevated CRP and ESR
name 4 common presenting signs/symptoms with cystitis. What is present in the urine?
dysuria + frequency + urgency + suprapubic pain
WBCs (but NO WBC CASTS) in the urine
what is main route of most cases of cystitis?
ascension of microbes from urethra to bladder
Name 3 things that can predispose males to cystitis
infants with congenital defects
vesicoureteral reflux
enlarged prostate in elderly men
What is pyelonephritis? How does it present?
ascension of infectious agents most commonly from bladder to the kidneys
fevers, chills + flank pain + CVA tenderness
blood (hematuria) and WBC casts in the urine
Why do UTIs occur 10X more common in women?
shorter urethras allow colonization by fecal flora
Name some other things that pre-dispose women to UTIs (6 listed)
DM
obstruction
catheterization
kidney surgery
pregnancy
GU malformations
(DOCK)tors (P)lay(G)round
Why would a patient have positive leukocyte esterase test?
bacterial UTI
What if a patient has a positive nitrite test?
gram negative bacterial UTI
Patient presents with a UTI and has a positive leukocyte esterase test, positive nitrite test and positive urease test, name 2 bugs that commonly cause these findings
Proteus, Klebsiella, etc.
Patient presents with a UTI and has a positive leukocyte esterase test, positive nitrite test, and negative urease test. Name a bug that causes these findings
E. coli = gram negative, urease negative
two bugs with negative urease test that can cause UTIs
E.coli + enterococcus
leading cause of UTI. colonies show green metallic sheen on EMB agar
E.coli
2nd leading cause of community acquired UTI in sexually active women
Staph saprophyticus
3rd leading cause of UTI that features large mucoid capsule and viscous colonies. What does this bug cause in alcoholics?
Klebsiella
Aspiration pneumonia in alcoholics
Some strains of this UTI-causing bug may produce red pigment and be drug resistant. Members of this genus may also cause osteomyelitis in DM and IVDU patients.
serratia marcescens
a nosocomial and drug resistant cause of UTI
enterobacter cloacae
motility causes a swarm on agar. positive urease test and is associated with UTIs and struvite stones. What are struvite stones made of?
Proteus mirabilis
Struvite = magnesium ammonium phosphates
nosocomial and drug resistant cause of UTIs. Blue-green pigment and fruity odor
Pseudomonas aeruginosa
List the top 3 most common causes of UTIs
- E. coli
- Staph saprophyticus
- Klebsiella
What are the ToRCHeS infections? How are they normally passed?
Toxoplasma gondii
Rubella
CMV
HIV
HSV-2
Syphilis
classic neonatal triad for rubella +/- one other finding
PDA or pulmonary artery hypoplasia
cataracts
deafness
+/- blueberry muffin rash (intradermal erythropoiesis)
what does the “blueberry muffin” rash of rubella and CMV signify?
intradermal erythropoiesis
Name 2 common ways that CMV is transmitted
sexual contact + organ transplants
maternal manifestations of CMV infection
usually asymptomatic or mono-like illness (monospot negative)
name 4 findings of neonatal CMV infection
hearing loss
seizures
petechial rash
blueberry muffin rash
name 2 causes of blueberry muffin rash in the neonate
rubella + CMV
name 2 common transmission routes of HIV
sexual contact + needle sticks
what does maternal manifestation of HIV infection depend on?
CD4 count
name 2 neonatal manifestations of HIV. What is most common neonatal manifestation of HIV?
recurrent infections + chronic diarrhea
Most commonly ASYMPTOMATIC at birth
name 2 ways for HSV-2 transmission
skin or mucous membrane contact
maternal manifestations of HSV-2 infection
usually asymptomatic or herpetic vesicular lesions
neonate with encephalitis + herpetic vesicular lesions
congenital HSV-2 infection
how is syphilis transmitted?
sexual contact
which maternal stages of syphilis are likely to result in fetal infection
primary = painless chancre
secondary = disseminated rash
how does neonatal syphilis often manifest?
stillbirth, hydrops fetalis
if a neonate survives a congenital syphilis infection, name 4 manifestations that occur later in life
- facial abnormalities = saddle nose, short maxilla, hemorrhagic rhinitis
- hutchinson’s teeth = centrally notched, widely spaced incisors
- saber shins
- CN 8 deafness
list 7 agents and associated diseases/syndrome that cause red rashes of childhood
- Measles virus
- Rubella virus
- Strep pyogenes = Scarlet Fever
- VZV = Chickenpox
- Parvo B19 = Erythema infectiosum
- HHV-6 = roseola
- Coxsackie A = hand-foot-mouth
post-auricular lymphadenopathy + rash beginning at head and moving down to form a fine truncal rash
rubella virus
cough + coryza + conjunctivitis followed by appearance of blue-white koplik spot on buccal mucosa followed by a rash beginning at the head and moving down to cover the hands and feet
measles
what is the difference between the rash of rubella vs. measles?
both start at the head and go downward, but measles hits the hands and feet, while rubella is primarily a fine, truncal rash that spares the hands and feet
vesicular rash that begins on the trunk and spreads to the face and extremities. lesions are of different “ages”
VZV chickenpox
macular rash over the body after several days of high fever. Usually affects infants and can present with febrile seizures
roseola HHV-6
slapped cheeks rash on face + hydrops fetalis in pregnant women + aplastic crisis in sickle cell folks. this agent has a tropism for bone marrow erythropoietic cells
parvovirus B19
erythematous, sand-paper rash with fever + sore throat
GAS = scarlet fever
vesicular rash on palms and sole + ulcers in the oral mucosa
coxsackie A = hand foot mouth disease
STI that may cause urethritis, cervicitis, PID, prostatitis, epididymitis, arthritis
N. gonorrhoeae
describe the discharge of N. gonorrhoeae STI
creamy and purulent
which STI causes a painless chancre? what stage of infection is this?
treponema pallidum = primary syphilis
which STI causes fever + lymphadenopathy + skin rashes + condyloma lata? what stage of infection?
treponema pallidum = secondary syphilis
which STI causes gummas + tabes dorsalis + general parsis + aortitis + argyll robertson pupils? what stage of infection?
treponema pallidum = tertiary syphilis
which STI causes a painful genital ulcer with inguinal adenopathy?
haemophilus ducreyi = chancroid
STI that causes painful penile, vulvar, or cervical vesicles and ulcers. Can cause systemic symptoms such as fever, headache, and myalgia
HSV2 > HSV1
STI that causes urethritis, cervicitis, conjunctivitis, Reiter’s syndrome (reactive arthritis), and PID
Chlamydia trachomatis (D-K)
STI that causes infection of lymphatics with genital ulcers + lymphadenopathy + rectal strictures
C. trachomatis (L1-L3 strains) = lymphogranuloma venereum
STI that causes vaginitis + straw-berry cervical mucosa + motile in wet prep
trichomonas vaginalis (protozoan)
STI that permits opportunistic infections + kaposi’s sarcoma + lymphomas
HIV leading to AIDS
STI that causes genital warts and koilocyte formation?
condylomata acuminata = HPV 6 and 11
STI that causes jaundice
HBV
STI that causes non-inflammatory, malodorous discharge with a fishy smell + positive whiff test + clue cells and may not be exclusively and STI
Gardnerella vaginalis
What are the top 2 bugs that cause PID? Which one is acute? Which one is sub-acute?
- Chlamydia trachomatis = most common bacterial STD in U.S. and causes subacute, often undiagnosed infections
- Neisseria gonorrhoeae = acute infections
What is the most common bacterial STI in the US?
Chlamydia trachomatis
What are some features of PID?
- Purulent cervical discharge
- Cervical motion tenderness = Chandelier’s sign
- Hydrosalpinx
- Endometritis
- Salpingitis
- Tubo-ovarian abscess
(P)elvic (CHEST)
What can syndrome can PID eventually cause?
Fitz-Hugh-Curtis syndrome = infection of the liver capsule and “violin string” adhesions of parietal peritoneum to liver
What are four risks associated with PID-induced salpingitis?
- Ectopic pregnancy
- Infertility
- Chronic pelvic pain
- Adhesions
2 viruses associated with newborn nursery noscomial infections
CMV and RSV
2 bugs associated with urinary catheter nosocomial infections
E. coli + proteus mirabilis
2 most common causes of bacterial nosocomial infections and their manifestations
- E. coli = UTIs
- Staph aureus = wound infections
nosocomial agent associated w/ respiratory equipment and burns
pseudomonas = “air-eugenosa” for respiratory devices
nosocomial agent associated with workers in the renal dialysis unit
HBV
nosocomial agent associated with hyperalimentation
candida albicans
nosocomial infection associated with water
legionella
2 viruses that cause rashes in unvaccinated children
rubella and measles
2 agents that cause meningitis in un-immunized children, one that colonizes the nasopharynx and one that may also lead to myalgia and paralysis
- H. flu type B = colonizes the nasopharynx
- poliovirus = may also lead to myalgia and paralysis
2 bugs that cause respiratory infections in unvaccinated children, one in the pharynx and one in the epiglottis
pharyngitis = Corynebacterium diphtheriae
epiglottitis = H. flu type B
grayish oropharyngeal exudate that may obstruct the airway and cause painful throat in an unvaccinated child. what are these gray exudates called?
C. diphtheriae = pseudomembranes
which bug, in an unvaccinated child, produces a toxin that causes necrosis in the pharynx, heart, and CNS tissue?
C. diphtheriae
fever w/ dysphagia, drooling, and breathing difficulty due to “cherry red” epiglottis in both un-immunized and fully immunized children?
H. flu type B = epiglottitis
pus, empyema, abscess
Staph aureus
pediatric infection, including epiglottitis
H. flu
pneumonia in CF or burns patient
pseudomonas
branching rods in oral infection with sulfur granules
actinomyces israelii
traumatic open wound
clostridium perfringens
surgical wounds
staph aureus
dog or cat bite
pateurella multocida
currant jelly sputum
klebsiella
positive PAS stain
tropheryma whipplei = Whipple’s disease
sepsis/meningitis in a newborn
GBS
needlestick to a healthcare provider
HBV
fungal infection in DKA or IC patient
mucor or rhizopus species
asplenic patients
(encapsulated microbes = SHiNE SKiS)
Strep pneumo
H. influenza
N. meningitidis
E. coli
Salmonella
Klebsiella pneumonia
Strep B (GBS)
chronic granulomatous disease
catalase-positive microbes, especially S. aureus
2 infections of neutropenic patients
candida albicans (systemic) + aspergillus
facial nerve palsy
borrelia burgdorferi = lyme disease
Cause of pneumonia in farmers & veterinarians?
Coxiella burnetii (rickettsia)
- Q fever
- also from unpasteurized milk from infected animals
